1. Field of the Invention
The present invention relates to a semiconductor processing apparatus and, more particularly, to a semiconductor processing apparatus capable of obtaining thermal stability.
2. Description of the Related Art
In a photo-resist process of semiconductor device fabrication, a resist solution is coated on a substrate such as a semiconductor wafer (hereinafter referred to as "a wafer" ) to form a resist film thereon. After a pattern is exposed, the wafer is supplied with a developing solution to be developed. A coating and developing apparatus has been conventionally used in performing a series of processing described above.
In the coating and developing apparatus, a heating apparatus for heating a wafer, a cooling apparatus for cooling the heat-treated wafer, a resist coating apparatus for coating the wafer with a resist solution to form a resist film thereon and a solution processing apparatus of a developing apparatus for supplying the wafer with a developing solution to perform predetermined development processing are individually provided.
The transfer of the wafer to/from these thermal processing apparatus and solution processing apparatus is performed by a transfer device. The transfer device is provided vertically with, for example, three pairs of tweezers which can carry the wafer into and out of each apparatus while holding the wafer. A pair of topmost tweezers out of the above tweezers is used exclusively for carrying the wafer out of the resist coating apparatus, and structured not to carry the wafer into and out of the heating apparatus having a high processing temperature. Namely, the pair of topmost tweezers is never warmed by the heating apparatus.
Thus, the wafer held by the topmost tweezers is hardly influenced by heat, and the heat-sensitive resist film never receives a thermal bad influence.
By the way, in a coating and developing apparatus of late years, in order to reduce an installation area, a heating apparatus, solution processing apparatus, and the like are more integratedly arranged as compared with the conventional apparatus. Consequently, there is a possibility that in the aforesaid coating and developing apparatus, heat generated by the heating apparatus exerts a bad influence on the solution processing apparatus.
Especially in the coating and developing apparatus of late years, a large-sized heating apparatus, solution processing apparatus, and the like corresponding to a wafer with a large area are used, whereby heat generated by the heating apparatus is increased in amount and in temperature. Accordingly, there is a possibility that in the aforesaid coating and developing apparatus, unintentional changes occur not only in the solution processing apparatus but also, for example, in the thickness of a resist film or a processing solution film.
Further, large-sized tweezers corresponding to the wafer with a large area are used in the recent coating and developing apparatus, thereby increasing the heat reserve capacity of the tweezers. Therefore, there is a possibility that in the recent coating and developing apparatus, heat is transmitted from the tweezers to the solution-processed wafer, for instance, the wafer on which a resist film has formed, thereby exerting a bad influence on the wafer. Also in this case, there is a possibility that unintentional changes occur in the thickness of a resist film or a processing solution film as described above.
Since the heating apparatus, solution processing apparatus, and the like are integrated and arranged in the aforesaid coating and developing apparatus, the maintenability for the heating apparatus and the solution processing apparatus is low, and hence improvement is required.